1. Field of the Invention
The present invention relates generally to a mobile communication terminal for providing an ad-hoc network service and a method for managing an ad-hoc network using the same. More particularly, this invention relates to a dual mode mobile communication terminal that can support a mobile communication network (e.g., a cellular network) service and an ad-hoc network service, and to a method for managing an ad-hoc network formed among such mobile communication terminals.
2. Description of the Related Art
With the development of mobile communication technology related to mobile communication terminals (e.g., mobile phones, Personal Digital Assistants (PDAs), and laptop computers), such terminals now employ a variety of functions. For example, a mobile phone could only provide wireless voice calling in its early stages of development, but now can support transmission of text and images in addition to voice calling.
Particularly, as technology for loading memory, which can store large multimedia files (e.g., moving images and music video) and data transmission technology are developed, a mobile communication terminal can now transmit/receive such multimedia files to/from other mobile communication terminals.
As such, while a variety of functions are added to mobile communication terminals, a communication method has been proposed by which mobile communication terminals can communicate with each other without passing through a mobile communication network such as a cellular network. Examples of such a communication method are 802.11 WiFi, 802.15 Wireless Personal Area Network (WPAN), Bluetooth®, Ultra Wide Band (UWB), Zigbee®, Infrared (IR) and 802.16 Wireless Metropolitan Area Network (WMAN).
An ad-hoc network refers to a network in which moving nodes (e.g., mobile communication terminals) having wireless interfaces autonomously communicate with each other using the above listed communication methods. That is, in the ad-hoc network, the moving nodes are connected to each other through a plurality of hops and then perform communication. Each moving node functions as an end node (e.g., a host) or an intermediate node (e.g., a router). Therefore, although a node intended to communicate with another node (where they are referred to as ‘ad-hoc network participation node’ or ‘ad-hoc network participants’) is not directly or indirectly connected to another node through a physical wireless link, the ad-hoc network allows the ad-hoc network participants to communicate with each other though other nodes.
In addition, the ad-hoc network allows the ad-hoc network participants to voluntarily set each other and to freely participate or secede to/from the network. However, the ad-hoc network has restrictions due to its energy sources, since it is battery operated. Also, the ad-hoc network causes frequent environment variations (e.g., since the participation nodes are moved) according to wireless network characteristics. Therefore, the ad-hoc network has a frequently varying network topology.
Accordingly, the conventional ad-hoc network has disadvantages in that it does not handle the network management well. In particular, the conventional ad-hoc network makes it difficult to allocate addresses to nodes and manage them.
The conventional mobile communication terminal, which is connectable to both the mobile communication network and the ad-hoc network, employs a method in which Internet Protocol version 6 (IPv6) address is statically allocated. However, since the introduction of the IPv6 address has been slow, configuration of the ad-hoc network using the mobile communication terminal has also been delayed. As well, although such IPv6 address is now used, the conventional method still has a drawback in that it cannot handle frequent variations in network topology.